Wet abrasive dispenser



April 24, 1956 G. HALL WET ABRASIVE DISPENSER Filed Feb. 24, 1953 INVENTOR. BCg EO/PGE LE0 HALL MJJJW A Trorawvzv United States Patent WET ABRASIVE DISPENSER George L. Hall, Atlanta, Ga.

Application February 24, 1953, Serial No. 338,351 5 Claims. c1. 51-8) This invention relates to a Wet abrasive dispenser and more particularly to apparatus which will mix and dispense fluids and solids or a combination of fluids for use in sand blasting, monumental carving, building cleaning, paint stripping, etc.

In the dispensing of abrasive and abrasive materials, it is often desirable to mix sand, granite dust, marble dust, banding sand, flint stone, and aluminum oxide or other similar abrasives with steam or steam vapor, re-agent or detergent chemicals, or abrasive liquids so that upon discharge from the dispenser, the direction and cutting quality of the abrasives may be more efliciently controlled.

In dry abrasive cleaning or blasting, the sand, marble, or granite dust or banding sand, used as an abrasive, is propelled by compressed air and strikes the surface onto which it is directed, then flies in every direction, striking many surfaces and objects which this material may damage. Another disadvantage of dispensing dry abrasives is that, since the abrasive is discharged in a dry state, considerable dust is created, making it necessary for the operator to wear a gas mask or similar device to protect his respiratory organs.

In event no gas mask or similar device is used, the flying abrasive or dust is usually inhaled into the respiratory organs of the operators and will also be inhaled by passersby, causing considerable discomfort which often results in a severe illness, commonly known as silicosis. In view of these conditions, numerous state and municipal authorities have passed legislation prohibiting the use of such dry sandblasting equipment except in enclosed areas and there is a movement on foot, at the present time, to abolish such practice entirely in certain sections of the country.

Another disadvantage of dry sandblasting is that it creates a tire hazard by generating sparks when the dry abrasives strike certain surfaces. Numerous explosions have occurred as a result of these sparks, when oil tanks, drums, etc. were being sandblasted with a dry abrasive. Other disastrous fires have originated in the same manner. On the other hand, wet sandblasting creates no sparks; indeed when steam, a smothering agent, is used, as a fluid in wet abrading, fires originating from any cause may quickly be snuffed out.

In conventional sandblasting, as described above, there is little or no control over the directions such dry abrasives will follow as they are discharged from the conminer resulting in considerable waste of the abrasive materials. Such operations require the use of expensive equipment such as air compressors, etc.

It is a generally known fact that most material used in sandblasting operations contains a high percentage of silica or quartz which, while insoluble in water, dissolves readily in hot solutions of the caustic alkalis (detergents). In its dry state, silica has no aflinity for dry alkalis which precludes the possibility of advantageously using alkali detergents with dry abrasives or even with wet abrasives unless they are kept in a heated condition. The use of ice such detergents with abrasives are highly desirable since the same greatly speeds up cleaning operations, especially the removal of paint from surfaces to be repainted. Since it has been determined that silica or quartz dissolves or is held in almost complete suspension in hot solution of the caustic alkalis, such a solution is of great advantage when abrading certain metals and in the polishing of marble or granite for decorative purposes or when abrading any surface where pitting may be a hazard, asin the case of abrading engine crank shafts, etc.

With the use of wet abrasives, on the other hand, the disadvantages mentioned above will be overcome; and, in addition, active detergent chemicals may be incorporated with this wet abrasive material to achieve a resulting decrease in the amount of time necessary to clean a given object. Also, where a fluid is incorporated with a dry abrasive, either at an elevated temperature or at a normal temperature, the abrasive qualities will be enhanced and the abrasives in this wet state may be more accurately directed against an object and with the elimination of the dust formation mentioned above.

Accordingly, it is an object of my invention to provide apparatus for mixing and dispensing wet abrasive materials whereby the pressure, consistency and temperature of a mixture of fluid and solid abrasive material may be controlled.

One of the objects of my invention is to provide a mixing apparatus providing for the introduction of hot alkali solutions to certain abrasive materials such as silica for the purpose of dissolving or holding in suspension the abrasive material in order to minimize the depth of its scratching ability and yet abrade the surface sufiiciently to produce a highly polished eifect.

Another object of my invention is to provide means for controlling the temperature of the above mentioned caustic alkali solution and the resultant mixture of same and abrasive material in order to control the depth of the scratching ability of the abrasive material since the lower the temperature of such abrasive solution the deeper same will cut into the surface to be treated, because the size of the cutting edges of the abrasive material is greatly reduced by increasing the temperature of the abrasive solution.

Another object of my invention is to provide an apparatus for mixing and dispensing wet abrasive materials, steam vapor, and detergents, which is economical in operation, simple and durable in structure, inexpensive to manufacture, and which may be operated with any exist-- ing steam or pressurized liquid supply obviating the necessity of purchasing additional costly equipment such as air compressors, high pressure pumps, etc.

Another object of my invention is to provide an apparatus for mixing and dispensing wet abrasive materials which has incorporated therewith certain safety devices which will automatically cut off the supply of fluid when a predetermined pressure within the apparatus has been reached.

Another object of my invention is to provide an apparatus for mixing and dispensing wet abrasive materials which has incorporated therewith certain devices which may be adjusted to automatically maintain any desired pressure at which the wet abrasive is discharged from the apparatus.

Another object of my invention is to provide an apparatus as described above which is provided with a tank or container having a filling means whereby only a predetermined amount of abrasive material may be introduced into the tank.

Another object of my invention is to provide an apparatus for mixing and dispensing wet abrasive materials which is eflicient and economical in operation, simple and durable in structure, and inexpensive to manufacture.

Another object of my invention is to provide an apparatus for mixing and dispensing wet abrasive materials which is light weight and easily transportable and which may be adapted to any standard fluid or steam pipe line or fluid dispensing apparatus.

Other and further objects and advantages of my invention will become apparent from the following description when taken in conjunction with the accompanying drawings in which like characters of reference designate corresponding parts throughout the several views, and where- Fig. 1 is a perspective view of a wet abrasive dispenser constructed in accordance with my invention.

Fig. 2 is a top view of the machine shown in Fig. 1.

Fig. 3 is a partially broken side elevation of the apparatus shown in Fig. 1.

Fig. 4 is a schematic diagram showing the operation of the control. mechanism incorporated with the apparatus shown in Fig. 1.

Referring now in detail to the embodiment chosen for purpose of illustration, numeral denotes a hollow cylindrical tank or container having a convex top 11 and a bottom 12 provided with a drain plug 13. Legs 14 support tank 10 in an upright position as shown in Fig. 3, and

a hollow filling pipe 15 extends down through top 11 to the mid-section of tank 10 and is open at the lower end, being provided with an external filling cap 16 which threadably engages the upper end. A pressure gauge 17 is provided to indicate the pressure within tank 10.

A fluid inlet pipe 18 enters through one side of cylinder Fig. 4, thereby actuating solenoid 23 to close valve 24 located at a remote position in line 19. Solenoid 23 and valve 24 are only required when attaching unit to plant or boiler steam. Apparatus, commonly known as steam cleaners, generally have some form of pressure control and such units may be operated with the present invention minus all three: pressurestat 22, solenoid 23, and valve 24, without departing from my invention.

Extending through the central periphery of tank It) at a point above the lower end of pipe 15 is a wet abrasive dispensing pipe 25 to which wet abrasive nozzle 26 is v,

connected through flexible hose connection 27 and a similar fluid dispensing nozzle 28 and flexible hose 29 are connected to fluid discharge valve 21. At the top of tank 10, I have provided a vent valve 30 which is used to open tank 10 to the atmosphere when desired.

When my apparatus is to be placed in operation, cap

16 is removed from pipe 15 and a dry abrasive 31 is introduced into tank 10, filling the lower part of tank 10 up to the lower end of pipe 15. Cap 16 is then replaced on pipe 15 and steam or other fluid under pressure is introduced into tank 10 by opening valve 20 which allows fluid to pass through pipe 18, this fluid being deflected by bottom 12, thus agitating the abrasive material 31 in tank 10. With nozzle 26 open, a mixture of fluid and abrasive is carried through hose connection 27 and out of nozzle 26, so that an operator can direct the flow of this material as desired. With fluid regulator valve 20 closed and fluid discharge valve 21' open, the operator may spray just the fluid alone by using nozzle 28; however, in some instances it may be desirable to use both nozzle 26 and nozzle 28 simultaneously, in which case both valves 20 and 21' should be opened.

With both valves 20 and 21' closed, pressure will build up in line 19 thereby actuating pressurestat 22 which in turn actuates solenoid 23 to close valve 24, thereby shut- 4 ting oif fluid to line 19. On the other hand, if either valve 20 or 21' were opened and material were to block the passage of fluid therethrough, pressurestate 22 would operate, thereby closing valve 24 to prevent a pressure build-up in line 19 or inside tank 10.

It is obvious that abrasive 31 may consist of any conventional dry abrasive such as sand, granite dust, marble dust, banding sand, flint shot, aluminum dioxide, or the like or, if desired, a wet abrasive or chemical could be introduced in its place when it is advisable to mix two fluids together, immediately prior to dispensing them. Fluid introduced through pipe 18 may be a gas, liquid or a vapor such as steam, steam vapor, hydrochloric acid, a chemical detergent, or any suitable solvent. It should be remembered, however, that the materials of construction used for my apparatus should be of a class which is not affected by chemical to be introduced therein.

One major feature of my device is that abrasives dispensed therethrough are wet and therefore reduce the danger of fire since the fluid which agitates the dry abrasive material in tank 10 completely surrounds this material and therefore reduces the tendency of the abrasive material to cause sparks, thereby reducing the fire hazard normally accompanying dry abrasive dispensing. In addition, the amount of abrasive material required to do a specific job is materially reduced since the effectiveness of wet abrasives dispensed by my apparatus is enhanced inasmuch as fluid completely surrounds the abrasive material due to agitation in the top section of tank 10.

It will be obvious that, while my present invention is designed primarily as a separate unit to be attached to some form of pressurized steam, steam vapor, or pressurized fluid, it can also be incorporated in a single steam vapor generating apparatus such as is commonly known as a steam cleaner as a combination steam cleaner and abrasive dispenser or that it could be combined with high pressure fluid pumping units as a high pressure abrasive washing machine.

It will be obvious to those skilled in the art that many variations may be made in the single embodiment shown and described without departing from the scope of my invention as defined by the appended claims.

I claim:

1. A wet abrasive dispenser comprising a tank provided with a bottom and a top, a filling pipe extending an appreciable distance into said tank through which abrasive material is introduced into said tank, said filling pipe being provided with means for closing said pipe after said abrasive material is introduced into said tank, the end of said pipe within said tank normally limiting the level of said abrasive introduced through said pipe into said tank, a fluid inlet pipe entering said tank and through which fluid is passed into said tank under pressure to agitate said abrasive material and discharge same from said tank. said inlet pipe terminating with one end in the form of an orifice adjacent said bottom of said tank, a control valve connected to said inlet pipe for controlling the amount of said vehicle introduced into said tank through said inlet pipe, a fluid supply line connected to said control valve through which same passes, a wet abrasive dispensing pipe terminating inside said tank so that as said fluid agitates said abrasive material a mixture of said abrasive material and said fluid will pass out of said tank through said wet abrasive dispensing pipe, and nozzle means connected to said abrasive dispensing pipe for dispensing such mixture.

2. A wet abrasive dispenser comprising a tank provided with a bottom and a top, a filling pipe extending an appreciable distance into said tank through which abrasive material is introduced into said tank, said filling pipe being provided with means for closing said pipe after said abrasive material is introduced into said tank, the end of said pipe within said tank normally limiting the level of said abrasive introduced through said pipe into said tank, a fluid inlet pipe entering said tank and through which fluid is passed into said tank to agitate said abrasive material, said inlet pipe terminating with one end adjacent said bottom of said tank, a control valve connected to said fluid inlet pipe for controlling the amount of said fluid introduced into said tank through said fluid inlet pipe, a fluid supply line connected to said control valve through which fluid passes, pressure control means in said fluid supply line for controlling the pressure of fluid passing through said fluid line, a wet abrasive dispensing pipe terminating inside said tank so that as said fluid agitates saidabrasive material a mixture of said abrasive material and said fluid will pass out of said tank through said wet abrasive dispensing pipe, and nozzle means connected to said wet abrasive dispensing pipe for dispensing said mixture.

3. A wet abrasive dispenser comprising a tank provided with a bottom and a top, a filling pipe substantially smaller than said tank extending into said tank through which abrasive material is introduced into said tank, said filling pipe being provided with means for closing said pipe, the end of said pipe normally limiting the level of material which is introduced through said pipe into said tank, a fluid inlet pipe entering said tank and through which fluid is passed into said tank to agitate said abrasive material, said inlet pipe terminating with one end adjacent said bottom of said tank, a control valve connected to said fluid inlet pipe for controlling the amount of said fluid introduced into said tank through said fluid inlet pipe, a fluid supply line connected to said control valve through which fluid passes, a pressurestat in said fluid supply line, a valve in said fluid supply line regulated by said pressurestat for controlling the pressure of fluid passing through said fluid supply line, a wet abrasive dispensing pipe terminating inside said tank so that as said fluid agitates said abrasive material a' mixture of said abrasive material and said fluid will pass vout of said tank through said wet abrasive dispensing pipe, nozzle means connected to said wet abrasive dispensing pipe for dispensing said mixture, nozzle means connected to said fluid supply line, and valve means connected for selectively discharging fluid from said fluid supply line through said last mentioned nozzle means.

4. A wet abrasive dispenser comprising a tank provided with a bottom and a top, a filling pipe extending through said top into said tank and terminating with a mouth substantially at the midsection of said tank through which abrasive material is introduced into said tank, to the level of said month, said filling pipe being provided with an external cap for closing said pipe, a fluid inlet pipe entering said tank and through which fluid is passed into said tank to agitate said abrasive material, said inlet pipe extending inwardly and downwardly and terminating with one end adjacent said bottom of said tank, a control valve connected to said fluid inlet pipe for controlling the amount of said fluid introduced into said tank through said fluid inlet pipe, a fluid supply line connected to said control valve through which fluid passes, a pressurestat in said fluid supply line, a valve in said from said fluid supply line through said last mentioned nozzle means.

5. A wet abrasive dispenser comprising a tank provided with a flat bottom and concave top, a filling pipe of substantially smaller diameter than said tank extending through said top into said tank and terminating with a mouth substantially at the midsection of said tank through which abrasive material is introduced into the bottom section of said tank to the level of said month, said filling pipe being provided with an external cap for closing said pipe, a fluid inlet pipe entering said tank and through which fluid is passed into said tank to agitate said abrasive material, said inlet pipe extending inwardly and downwardly and terminating with one end adjacent said bottom of said tank, a control valve on the other end of said fluid inlet pipe for controlling the amount of said fluid introduced into said tank through said fluid inlet pipe, a fluid supply line connected to said control valve through which fluid passes, a pressurestat in said fluid supply line, a valve in said fluid supply line regulated by said pressurestat for controlling the pressure of fluid passing through said fluid supply line, a wet abrasive dispensing pipe terminating inside said tank at a position above said mouth of said filling pipe so that as said fluid agitates said abrasive material a mixture of said abrasive material and said fluid will pass out of said tank through said wet abrasive dispensing pipe, nozzle means connected to said wet abrasive dispensing pipe for dispensing said mixture, nozzle means connected to said fluid supply line between said pressurestat and said tank, and valve means connected for selectively discharging fluid from said fluid supply line through said last mentioned nozzle means.

References Cited in the file of this patent UNITED STATES PATENTS 

